From c989e74446836ce8a00ae002d4c229c81e1f7905 Mon Sep 17 00:00:00 2001 From: Klaus117 Date: Tue, 4 Mar 2025 12:44:09 -0800 Subject: GH-130415: Narrow int to 0 based on boolean tests (GH-130772) --- Lib/test/test_capi/test_opt.py | 31 ++++++++++++++++++++++ Misc/ACKS | 1 + .../2025-03-03-01-21-04.gh-issue-130415.ibOV6B.rst | 1 + Python/optimizer_bytecodes.c | 2 +- Python/optimizer_cases.c.h | 2 +- Python/optimizer_symbols.c | 3 +++ 6 files changed, 38 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-03-03-01-21-04.gh-issue-130415.ibOV6B.rst diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py index b7083db..a4faab2 100644 --- a/Lib/test/test_capi/test_opt.py +++ b/Lib/test/test_capi/test_opt.py @@ -1499,6 +1499,37 @@ class TestUopsOptimization(unittest.TestCase): # But all of the appends we care about are still there: self.assertEqual(uops.count("_CALL_LIST_APPEND"), len("ABCDEFG")) + def test_narrow_type_to_constant_int_zero(self): + def f(n): + trace = [] + for i in range(n): + # zero is always (int) 0, but we can only prove that it's a integer: + false = i == TIER2_THRESHOLD # this will always be false, while hopefully still fooling optimizer improvements + zero = false + 0 # this should always set the variable zero equal to 0 + trace.append("A") + if not zero: # Kept. + trace.append("B") + if not zero: # Removed! + trace.append("C") + trace.append("D") + if zero: # Removed! + trace.append("X") + trace.append("E") + trace.append("F") + if zero: # Removed! + trace.append("X") + trace.append("G") + return trace + + trace, ex = self._run_with_optimizer(f, TIER2_THRESHOLD) + self.assertEqual(trace, list("ABCDEFG") * TIER2_THRESHOLD) + self.assertIsNotNone(ex) + uops = get_opnames(ex) + # Only one guard remains: + self.assertEqual(uops.count("_GUARD_IS_FALSE_POP"), 1) + self.assertEqual(uops.count("_GUARD_IS_TRUE_POP"), 0) + # But all of the appends we care about are still there: + self.assertEqual(uops.count("_CALL_LIST_APPEND"), len("ABCDEFG")) def global_identity(x): return x diff --git a/Misc/ACKS b/Misc/ACKS index 7bf1d9c..2526e78 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -1061,6 +1061,7 @@ Detlef Lannert Rémi Lapeyre Soren Larsen Amos Latteier +Keenan Lau Piers Lauder Ben Laurie Yoni Lavi diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-03-03-01-21-04.gh-issue-130415.ibOV6B.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-03-03-01-21-04.gh-issue-130415.ibOV6B.rst new file mode 100644 index 0000000..636b221 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-03-03-01-21-04.gh-issue-130415.ibOV6B.rst @@ -0,0 +1 @@ +Improve JIT understanding of integers in boolean context. diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c index c4e4b28..2aeed24 100644 --- a/Python/optimizer_bytecodes.c +++ b/Python/optimizer_bytecodes.c @@ -406,7 +406,7 @@ dummy_func(void) { op(_TO_BOOL_INT, (value -- res)) { if (!optimize_to_bool(this_instr, ctx, value, &res)) { sym_set_type(value, &PyLong_Type); - res = sym_new_type(ctx, &PyBool_Type); + res = sym_new_truthiness(ctx, value, true); } } diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h index 397184d..9555e14 100644 --- a/Python/optimizer_cases.c.h +++ b/Python/optimizer_cases.c.h @@ -178,7 +178,7 @@ value = stack_pointer[-1]; if (!optimize_to_bool(this_instr, ctx, value, &res)) { sym_set_type(value, &PyLong_Type); - res = sym_new_type(ctx, &PyBool_Type); + res = sym_new_truthiness(ctx, value, true); } stack_pointer[-1] = res; break; diff --git a/Python/optimizer_symbols.c b/Python/optimizer_symbols.c index e8a3b91..28a2791 100644 --- a/Python/optimizer_symbols.c +++ b/Python/optimizer_symbols.c @@ -299,6 +299,9 @@ _Py_uop_sym_set_const(JitOptContext *ctx, JitOptSymbol *sym, PyObject *const_val else if (type == &PyBool_Type) { _Py_uop_sym_set_const(ctx, value, Py_False); } + else if (type == &PyLong_Type) { + _Py_uop_sym_set_const(ctx, value, Py_GetConstant(Py_CONSTANT_ZERO)); + } // TODO: More types (GH-130415)! make_const(sym, const_val); return; -- cgit v0.12